Conformationally Constrained Glycosyl Donors as Tools to Control Glycosylation Outcomes.

The stereoselective synthesis of oligosaccharides remains one of the biggest challenges in carbohydrate chemistry. Many factors, including reaction conditions and the type of glycosyl donor and acceptor used, can affect the outcome of glycosylation reactions. In this Perspective, we discuss methods aimed to control the reactivity and stereoselectivity of glycosylation reactions using conformationally constrained glycosyl donors, with a focus on more recently developed chemistry.